[1]} recovered for the first time PDS 70 b in the narrow filter NB4.05 of VLT/NACO centred at Br \(\alpha \)  (\(\lambda _{\mathrm {c}}=4.05~\) m, effective widthFrom the SVO at http://svo2.cab.inta-csic.es/theory/fps3/index.php?id=Paranal/NACO.NB405. The width of 0.02 \(\) m mentioned by several (e.g. [2]}, [3]}, [4]}, [5]}, [6]}, [1]})
is not correct. However, this does not change their results. The incorrect value was from http://www.eso.org/sci/facilities/paranal/decommissioned/naco/inst/filters.html (up to 2021 January), which nevertheless provides the right filter transmission profile. \(\Delta \lambda =0.0616~\) m) as part of the MIRACLES survey [6]}.
However, there is no evidence for a shock excess at NB4.05, where the thermal emission from the atmosphere is significant. Also, using VLT/SINFONI, [9]} and [10]} did not detect a shock excess in Br \(\gamma \)  at 2.166 \(\) m, nor did [11]} in Pa \(\beta \)  with Keck/OSIRIS.
We note that this is
consistent with the models of [12]}, which predict that these lines should be much lower than the photospheric emission. The moderate resolution of the instruments dilutes any shock excess into the continuum.
